Manifold mounting



April 3 c, B. LEACH 2,635,418

MANIFOLD MOUNTING Filed Nov. 9, 1949 3nnentor (Ittornegv Patented Apr.21, 1953 MANIFOLD MOUNTING Clayton B. Leach, Pontiac, Mich, assignor toGeneral Motors Corporation, Detroit, Mich., a corporation of DelawareApplication November 9, 1949, Serial No. 126,335

7 Claims.

This invention relates to exhaust manifolds for internal combustionengines and the like, and particularly to means for clamping a tubularmanifold to the cylinder head or other structure containing the exhaustports.

The invention concerns primarily, though not exclusively, an improvedclamping arrangement for manifolds made of seamless or welded steeltubing. In the use of such a manifold which is generally circular incross section, it is preferable that the side or wall of the manifoldcontaining openings in registry with the cylinder head exhaust ports besocketed or recessed in the ported side of the cylinder head, therebyobtaining a satisfactorily tight seal around the exhaust ports withoutthe necessity of providing a separate gasket between the manifold andcylinder head.

A problem has existed in the use of these types of manifolds inobtaining a proper clamping arrangement which will hold the manifoldtightly in place under all operating conditions and which is unaffectedby changes in temperature of the manifold. The use of plain strap orU-type clamps engaging the exposed portion of the manifold have beenfound less than satisfactory due to the fact that when the exposedportion of the tube becomes red-hot in operation it tends to collapse acertain amount under the pressure of the clamp, resulting in asubsequently loose mounting of the manifold.

' As the result of a study I have made to correct this difificulty, Idiscovered that the inner portion of the manifold tube in contact withthe cylinder 'head remains relatively 0001 during engine operation ascontrasted with the outer portion of the tube which becomes excessivelyhot. From this finding it was reasoned that if a clamping area could bedesigned which confined the clamping pressure to the inner portion ofthe tube, the heating up of the outer portion in operation would notaffect the tightness of fit of the manifold on the cylinder head.

Accordingly, it is the prime object of my invention to provide animproved arrangement for clamping a tubular exhaust manifold to theexhaust port structure of an internal combustion engine or the like.

. A further object of my invention is to provide tubular exhaustmanifold clamping means which is not subject to manifold temperaturechanges in operation.

A still further object of my invention is to provide an improvedclamping arrangement for tubular exhaust manifolds wherein the clamping2 pressure is applied solely to the relatively cool operating portionsof the manifold.

Other objects and advantages of this invention will be apparent from thefollowing description, having reference to the drawing wherein:

Figure l is a side elevational View of a conventional internalcombustion engine incorporating my improved exhaust manifold clampingmeans.

Figure 2 is an enlarged sectional view of the cylinder head with themanifold in place, taken substantially on line 22 of Figure 1.

Figure 3 is a fragmentary view similar to Figure 2, showing a modifiedform of my clamping means.

Figure 4 is a fragmentary view in side elevation of the form of myinvention shown in Figure 3.

Figure 5 is a view similar to Figure 2' but showing still anothermodification of my improved clamping means.

Figure 6 is a fragmentary view in side elevation showing the form ofclamping means of Figure 5.

Referring now to the drawing illustrating my invention, I have shown thesame applied, for example, to an overhead valve type internal combustionengine designated generally by the numeral I. As shown in Figure l, theengine includes a conventional crankcase and cylinder block structure 2on which is a cylinder head 3 forming the usual combustion chambers (notshown) above the engine cylinders and having side openings or ports 4,5, 6, 1, 8 and 9 leading outward from the chambers to the exhaustmanifold Ill. H represents the usual cover enclosing the rockers andlubrication system for the valves located in the cylinder head '3.

As will be seen in Figure 2, the side face M of the cylinder head 3 iscylindrically recessed as at I5 to socketably receive the inner sidewall portion l6 of the generally cylindrically shaped manifold In, thisrecess extending the full length of the cylinder head and in line withthe ports 4-9. Opposite and in registry with each of these ports is anopening ll in the wall H; of the manifold through which the gases areintroduced into the manifold for conduction longitudinally therethroughto an exhaust outlet pipe l8. At spaced points along the manifold l0,and preferably approximately opposite the openings H, are formedindentations 2D and 2| adjacent both sides of the recess l5. Theseindentations which may be formed by any suitable swaging operation onthe manifold provide abutment surfaces 22 which are substantiallyparallel with the side face ll of the cylinder head and spaced outwardlyonly a short distance therefrom. The face It provides cooperatingabutment surfaces for lugs 23 which serve to hold the manifold I tightlyagainst the recess l5. These lugs in the form shown in Figure 2 aregenerally of L-section having legs 24 overlying the abutment surfaces 22andjlegs. 25'at right angles thereto which engage endwise with thecylinder head face l4. Studs or bolts 26 threadedly engaging thecylinder head 3 are provided which pass through the legs 24 and serve tohold the parts in assembled relation.

As will be apparent, since; the. inner wall'pors tion [6 of the manifoldI6 is in closeengagement' with the large mass of the cylinder head 3, it

will tend to remain at relatively low tempera tures during engineoperation. Further, since the clamping pressure of the lugs 23 isapplied as the bolts 26 are drawn up on the legs 24, the fu'lcrum'of thelever action being located at theinner ends of the legs 25.

Instead of using L-section lugs 23 as-shown in Figure 2, plain flatwashers 39 may be substituted as shown in Figures 3 and 4. To provide asimilar lever action by the lugs 30 a cylinder head 3 has been modifiedto provide inclined lug abutment surfaces 3| on each side of the recessI5. These abutment surfaces 3| incline parallel to the tubular axis ofthe manifold and toward the exhaust ports 4-9, the inner extremities ofthese surfaces being spaced a slight distance-inwardly of the cylinderhead from the abutment surfaces 22 provided on the manifold. When thebolts 26 are drawn up, thelugs 30 tend to fulcrum about their outer ends32v on thecylinder head, thereby applying an adjustable clampingpressure against the manifold surfaces 22.

In Figures and 6 I have employed the sameinclined abutment surfaces 3!on the cylinder head 3" buthave modified the lugs to provide forclamping each of them with two bolts 26 instead of one. The indentations35 in the manifold ID are elongated longitudinally of the latter toaccommodate the elongated lugs 36 as will be clear from .Figure 6.

The location of the indentations and lugs longitudinally of the manifoldmay be selected as desired, although it is preferable that they beplaced. opposite or substantially opposite the exhaust ports. Two sucharrangements shown, are in Figure l-wherein the lugs are located inoppositely. offset relation to each port, and in Figure 6 whereinthelugs v36 are located directly adjacent opposite'sides of the ports.

I claim:

1. In a multi-cylinder internal combustion engine or the like, structureforming ports for the passage of exhaust gases outwardly from the enginecylinders, an exhaust manifold for conducting the gases from the outer,ends of said ports toward one end of the. engine, said manifold being oftubular formation with one side adapted for close mating engagementwiththe external surface of said structure, said side bein formed withopenings in registry with said ports,

indentations formed in the surfaceofthe mam-- fold closely adjacent-saidexternalsurface, and

4 clamping means engaging said indentations and secured to saidstructure.

2. In a multi-cylinder internal combustion engine or the like, acylinder head having exhaust ports in communication with the enginecylinders, the external surface of said head adjacent and between saidports forming a generally cylindrical recess; a tubular manifoldsocketed in said'recessand provided with side openings in registry withsaid ports, opposite walls of said manifold outwardly adjacent saidrecess being provided with indentations, lugs engaging saidindentations, and members clamping said lugs to the cylinder'head.

3'. In an internal combustion engine or the like, structure defining aplurality of cylinder exhaustports in .spaced relation longitudinally ofthe engine, the external surface of said structure between and adjacentsaid ports being recessed to socketably receive one side of a tubularmanifold, a tubular manifold socketed insaid recess and having side.wall openings in registry with said ports, seats on the external surfaceofv said manifold outwardly adjacent said recess, clamping means forurging the manifold tightly against said structure including lugswithholts extending therethrough and into said-structure, saidlugsbeingin abutment with said seats and structure on opposite sides only oftheir respectivev bolts.

4. In an internal combustion engine or the like, structure defining aplurality of cylinderexhaust ports in spaced relation longitudinally ofthe engine, a tubular manifold having a side wall recessed within saidstructure and provided with apertures in registry with. said ports,indentations-in the. periphery of the manifold forming lug abutmentsurfaces adjacent said structure on opposite sides ofv said. ports, lugsengaging said. abutment surfaces, and members securing the lugs-to said.structure, said structure'being provided with lug abutmentsurfacesparallel with thetubular axisof. the manifoldand incliningrecessedwithin said structure and provided with apertures in registry with saidports, indentations in the periphery of the manifold forming lug.abutment surfaces adjacent said structure on surfaces on said structureadjacent saidindentations, L-section lugs each having a first leg engaging an abutment surface on said manifold.

and a secondleg engaging the adjacent abutment surface on saidstructure,and members extending through said first legs and threadedly anchoredinthe structure for clamping the manifold in place.

6. In an internal combustion engineer the like, structure defining aplurality of exhaust ports in spaced apart relation along one side ofthe engine, a tubular manifold with one side in close mating engagementwith the external surface of said structure, said last named side beingprovided with wall openings in registry with said ports, seats providedon the external surface of the manifold closely adjacent said last namedside, and members clampingly engaging said seats and'secured to saidstructure.

7. In. an external manifold for connecting'a plurality ofexhaustports-spaced along one side 5 of an engine, said manifold being tubularin section with one side Wall of the tube adapted to closely mate withthe external surface of the engine surrounding said ports and providedwith openings adapted to register With said ports, 5

seats provided on the external surface of the tube for engagement byclamping means secured to the engine, said seats being located onportions of the tubes external surface closely adjacent said side Wall.

CLAYTON B. LEACH.

References Cited in the file of this patent UNITED STATES PATENTS Number10 Number Name Date Wahlberg Sept. 30, 1941 Jacobs Dec. '7, 1948 WessmanJuly 12, 1949 Amundson May 1, 1951 FOREIGN PATENTS Country Date GreatBritain July 25, 1929

